Metastatic squamous cell carcinoma of the neck from an unknown primary: management options and patterns of relapse

Management of squamous cell carcinoma of undetermined primary tumors in the head and neck region is controversial. Here we report the Southern California Kaiser Permanente experience with these patients.

From January 1969 through December 1994, 106 patients were eligible for this retrospective analysis. Distribution of nodal staging was as follows: 14 N1, 27 N2A, 39 N2B, 2 N2C, and 24 N3. Initial treatment included excisional biopsy alone in 12, radical neck dissection alone in 29, radiotherapy alone in 24, excisional biopsy followed by radiotherapy in 15, and radical neck dissection plus postoperative radiation in 26 patients.

Except for two patients, all patients have had a minimum follow-up of 5 years. Overall, 57 patients (54%) have had recurrences. Only two patients (3%) who had received radiotherapy as part of their initial treatment had an appearance of a potential primary site inside the irradiated field vs 13 patients (32%) who had not received radiotherapy (p =.006). Combined modality therapy resulted in fewer neck relapses, particularly in patients with advanced neck disease. Including salvage, surgery alone as the initial treatment resulted in 81% ultimate tumor control above the clavicle for patients with N1 and N2a disease without extracapsular extension. The 5-year survival for the entire population was 53%. Radiotherapy alone resulted in poor survival in patients with advanced/unresectable neck disease. No significant difference in survival based on the initial treatment was found. The statistically significant adverse factors in determining survival included advanced nodal stage and the presence of extracapsular extension.

Radiotherapy is very effective in reducing the rate of appearance of a potential primary site. However, in the absence of advanced neck disease (N1 and N2A without extracapsular extension), radiotherapy can be reserved for salvage. Radiotherapy alone results in poor outcomes in patients with advanced/unresectable neck disease, and incorporation of concurrent chemotherapy and cytoprotective agents should be investigated.